Cleaner

ABSTRACT

The present disclosure relates to a cleaner including a cleaner main body having a controller, a wheel cover mounted on the cleaner main body, a driving module coupled to the wheel cover to be movable up and down, a driving wheel coupled to the driving module and configured to be rotatable by receiving driving force from the driving module, a suspension configured to guide the upward and downward movement of the driving module and absorb impacts while the driving module is moved up and down, a link member rotatably installed on the wheel cover, and rotated by being in contact with a protrusion of the driving module when the driving module is moved downward by a preset distance, and a switch pressed in response to the rotation of the link member to transfer a signal to the controller.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority under 35 U.S.C. § 119 to KoreanApplication No. 10-2016-0184441, filed on Dec. 30, 2016, whose entiredisclosure is hereby incorporated by reference.

BACKGROUND 1. Field

The present disclosure relates to a cleaner having driving wheels formoving a main body of the cleaner.

2. Background

A cleaner is a device that may perform a cleaning function, such asmopping or suctioning dust or other foreign materials. The cleaner mayperform the cleaning function on a floor surface and may include wheelsfor moving a main body of the cleaner along the floor surface.

One type of cleaner may include wheels that are not driven and are rollto enable the cleaner to move when an external force, such as a push byuser, is applied to a cleaner main body to move the cleaner main bodyrelative to the floor. Other types of cleaners may be self-propelled.For example, one type of cleaner may have driven wheels thatautomatically rotate to move a main body based on receiving adirectional input, such as sensing a movement of a cleaning nozzle bythe user. In another example, a robot cleaner (also referred to as anautomated cleaner) may perform a cleaning function while traveling byitself without a user's manipulation. These and other types ofself-propelled cleaners may use driving wheels that are rotated based onreceiving a driving force from a driving motor.

In order for the cleaner to have stable travel performance, the drivingwheels should remain in contact to the floor surface to transfer thedriving force even if the floor is uneven or cleaner moves through otherchanges in the floor surface. Consequently, a shock or impact to adriving wheel that is generated while the cleaner moves along a floorsurface may be cushioned or buffered so that the driving wheel remainsin contact with the floor surface.

With regard to buffering a shock or impact to a wheel of a cleaner,Korean Patent Publication No. 10-2016-0121844 (laid open on Oct. 21,2016) discloses a suspension structure in which a driving wheel isconnected to a driving arm that rotates centering on a rotating shaft,and an elastic member is connected to a housing and the driving arm toelastically support the driving arm. This structure exhibits suspensionefficiency that differs depending on a rotating direction of the drivingwheel. For example, this suspension structure may provide a certainlevel of suspension performance when the driving wheel rotates in acertain direction (e.g., clockwise), but may provide a reduced levels ofsuspension performance when the driving wheel rotates in anotherdirection (e.g., counterclockwise). Furthermore, this suspensionstructure provides a driving motor that is connected to one side of thedriving arm and has a gear portion therein, and the driving wheel isconnected to another side of the driving arm, such that the drivingmotor, the driving arm and the driving wheel need installation spacesthat may thereby occupy a large volume in the cleaner.

The above reference is incorporated by reference herein whereappropriate for appropriate teachings of additional or alternativedetails, features and/or technical background.

A driving unit, which includes the driving wheel and the driving motor,may be formed as a module that includes a connection mechanism to couplethe driving unit to the cleaner. The driving unit may also include awire connection mechanism for electrically connecting the driving motorto a power supply in the cleaner. Furthermore, an additional component(e.g., a cover) that is separate from the driving unit, may be mountedto the driving unit upon a final assembly. Such a complicated assemblingstructure may increase a defect rate of the driving unit and may causeundesirable secondary effects in which other components in the cleanermay be damaged when the modular driving unit is installed in or removedfrom the cleaner.

In addition, the driving wheel may stop rotating when the cleaner mainbody is obstructed by an obstacle, or the driving wheel may continue torotate even when the cleaner main body is lifted by the user. Thesetypes of wheel movements may reduce a stability of the cleaner and mayreduce user's satisfaction with the cleaner.

BRIEF DESCRIPTION OF THE DRAWINGS

The embodiments will be described in detail with reference to thefollowing drawings in which like reference numerals refer to likeelements, and wherein:

FIG. 1 is a perspective view illustrating one embodiment of a cleaneraccording to the present disclosure;

FIG. 2 is a lateral view of the cleaner illustrated in FIG. 1;

FIGS. 3 and 4 are perspective views of a wheel assembly of FIG. 2,viewed from different directions;

FIGS. 5 and 6 are conceptual views illustrating that wheel assembliesare detachably coupled to a lower portion of a cleaner main bodyillustrated in FIG. 2;

FIGS. 7 and 8 are exploded perspective views illustrating the wheelassembly of FIG. 3, viewed from different directions;

FIG. 9 is a sectional view of the wheel assembly of FIG. 3, taken alongthe line A-A;

FIGS. 10 and 11 are conceptual views illustrating a state in which thedriving wheel is moved upward and a state in which the driving wheel ismoved downward, in the wheel assembly of FIG. 3;

FIG. 12 is an exploded perspective view of a driving module illustratedin FIG. 7;

FIG. 13 is a sectional view of the wheel assembly of FIG. 3, taken alongthe line B-B;

FIG. 14 is a conceptual view illustrating a state in which the drivingmodule is moved upward in the wheel assembly of FIG. 3, viewed from afront surface (a) and a rear surface (b), respectively;

FIG. 15 is a conceptual view illustrating a state in which the drivingmodule is moved downward in the wheel assembly of FIG. 3, viewed fromthe front surface (a) and the rear surface (b), respectively; and

FIG. 16 is a conceptual view illustrating a link member illustrated inFIG. 14.

DETAILED DESCRIPTION

Hereinafter, a cleaner according to the present disclosure will bedescribed in detail with reference to the accompanying drawings. FIG. 1is a perspective view illustrating one example of a cleaner (alsoreferred to as an autonomous cleaner or a robot cleaner) 100, and FIG. 2is a lateral view of the cleaner 100. The robot cleaner 100 may performa function of cleaning a floor or other horizontal surface whiletraveling without user control in a predetermined area. The robotcleaner 100 may clean the floor by suctioning dust and foreign materialson the floor or by mopping the floor.

The cleaner 100 may include a cleaner main body (or main body) 110 anddriving wheels 123. The cleaner main body 110 may define an appearanceof the cleaner 100. The cleaner main body 110 may house variouscomponents, such as a controller (not shown) for controlling theoperation of the cleaner 100.

One or more of the driving wheels 123 that rotate to provide a force tomove the cleaner 100 may be provided on the cleaner main body 110. Thedriving wheels 123 may rotate based on receiving a driving force from adriving motor 122 b (see FIG. 9). In one example, the driving motor 122b may be reversible, and a rotating direction of the driving motor 122 bmay be controlled by the controller. Accordingly, the driving wheels 123may be selectively rotated in one direction (e.g., clockwise) or anotherdirection (e.g., counterclockwise). In another example, the drivingmotor 122 b may provide the driving force in a single direction, and thecontroller may selectively activate one or more gears or otherintermediate component to change a direction that the driving force isapplied to the driving wheel 123.

In one example, the driving wheels 123 may be provided on both left andright sides of the cleaner main body 110, respectively. In anotherexample (not shown in the drawings), a single driving wheel 123 may beprovided at one section of the cleaner main body 110 of the cleaner mainbody 110. The cleaner main body 110 may be moved or rotated forward,backward, to the left, or to the right by operation of the drivingwheels 123. The driving wheels 123 may be configured to be drivenindependently of each other. To this end, each of the driving wheels 123may be driven by a different driving motor 122 b. In anotherimplementation, the driving wheels 123 may receive a driving force froma single driving motor 122 b.

The cleaner 100 may further include at least one auxiliary wheel 140that may roll and does not receive a driving force. The auxiliary wheel140 may support the cleaner main body 110 together with the drivingwheels 123 and may assist the movement of the cleaner 100 by the drivingwheels 123. The auxiliary wheel 140 may be positioned at a front of thecleaner main body 110 to support a cleaner head 150. As shown in FIG. 2,the auxiliary wheel 140 may also be positioned at one or more othersections of the cleaner main body 110, such as a rear section oppositethe cleaner head 150 (e.g., under a dust container 160).

The cleaner head 150 may include at least one of a suction unit or a mopunit according to a cleaning function to be performed by the cleaner100. The cleaner head 150, as illustrated in FIGS. 1 and 2, may bearranged in a form protruding from the cleaner main body 110, or may beprovided on a lower portion of the cleaner main body 110. The cleanerhead 150 may be provided with an opening (not shown), and the openingmay be formed to face the floor surface. The cleaner head 150 may alsoinclude a roller 151 which is configured to extend through the openingto contact and clean the floor in a rotating manner. The roller 151 maybe detachably mounted in the opening. As previously described, theauxiliary wheel 140 may also be provided on the cleaner head 150.

When the cleaner 100 is configured to perform a vacuuming function tosuction dust and foreign substances from the floor surface, the cleanerhead 150 may correspond to a suction unit. The suction unit may beconfigured to suction air containing the dust and foreign materialsusing suction force generated by a motor (not shown) and a fan (notshown) in the cleaner 100. In the suction unit, the roller 151 maycorrespond to a brush unit that includes one or more brushes or bladesthat extend through the opening to contact or sweep the floor surface.

The dust and foreign substances included in air suctioned through thesuction unit may be filtered and collected in a dust container 160. Thefiltered air that is separated from the dust and foreign materials maythen be discharged back outside of the cleaner 100. The cleaner mainbody 110 may be provided with an intake flow path (not shown) thatguides a flow of suctioned air from the cleaner head 150 to the dustcontainer 160, and an exhaust flow path (not shown) that guides a flowof filtered air from the dust container 160 to the outside of thecleaner 100. The dust container 160 may be provided with at least one ofa filter or a cyclone to filter the dust and foreign materials from thesuctioned air from the cleaning head 150.

The cleaner 100 may include a dust container cover 170 covering the dustcontainer 160. When the dust container cover 170 is provided to cover anupper surface of the dust container 160, the dust container 160 may beprevented from being separated from the cleaner main body 110 by thedust container cover 170. In the example shown in FIG. 2, the dustcontainer cover 170 may be connected to the cleaner main body 110 by ahinge and may rotate around the hinge to open or close the dustcontainer 160. In operation of the cleaner 100, the dust container cover170 may be fixed to the dust container 160 or the cleaner main body 110to cover an upper surface of the dust container 160.

When the cleaner 100 is configured to perform a mopping function and tomop the floor, the cleaner head 150 may include the mop unit or moproller. The mop unit may be detachably mounted on the lower portion ofthe cleaner main body 110. In one example, the cleaner 100 may use onetype of roller 151 (e.g., a brush unit) for performing the vacuumingfunction and another type of roller 151 (e.g., a mop unit) to performthe mopping function. For example, the roller 151 for the mop unit mayinclude an absorbent surface that is designed to hold a cleaning fluidor water for mopping. Thus, the mop unit may be mounted on the cleanermain body 110 in place of the suction unit or, alternatively, a moppingroller for the mop unit may be attached to the opening of the cleaninghead 150 in place of the brush unit. Accordingly, the user mayselectively mount different cleaning heads 150 corresponding to one ofthe suction unit or the mop unit (or other type of cleaning head)according to the cleaning function. It should be appreciated that othertypes of cleaning heads 150 or rollers 151 may be used to providedifferent cleaning functions.

In certain implementations, the controller may modify one or moreoperations of the cleaner 100 based on whether the cleaning head 150corresponds to the suction unit or the mop unit. For example, thecontroller may deactivate a suction motor in the main cleaner body 110when the mop roller is installed. In other example, the controller maymodify a rotational speed of the roller 151 based on whether thevacuuming function or the mopping function is being performed.

The cleaner main body 110 may be provided with a sensing unit (orsensor) 180 that detects an aspect of a surrounding environment of thecleaner main body 110. The sensing unit 180 may include, for example, animage sensor, an electromagnetic frequency (EMF) sensor that detects EMFemissions by the cleaner 100 or another object (e.g., a charging base),etc. The controller may sense an obstacle, detect a land feature, orgenerate a map of a travel area based on data on the surrounding areathat are detected through the sensing unit 180. Although FIGS. 1 and 2show the sensing unit 180 as being positioned on a front section of thecleaner main body 110, the sensing unit 180 may be additionally oralternatively positioned on a rear, side, top, and bottom surface of thecleaner main body 110.

Hereinafter, the driving wheels 123 provided on the cleaner 100 will bedescribed in more detail. FIGS. 3 and 4 show perspective views of thewheel assembly 120, viewed from different directions, and FIGS. 5 and 6show the wheel assembly 120 being detachably coupled to the lowerportion of the cleaner main body 110.

Referring to FIGS. 3 to 6, the wheel assembly 120 may include a drivingmodule 122 for generating a driving force, the driving wheel 123 that isconfigured to be rotatable based on receiving the driving force from thedriving module 122, and a wheel cover 121 provided to cover upper (e.g.,in a direction away from the floor surface being cleaned) portions ofthe driving module 122 and the driving wheel 123.

The wheel assembly 120 may be detachably coupled to the cleaner mainbody 110. As shown in FIGS. 5 and 6, the cleaner main body 110 mayinclude with a mounting portion (or mounting recess) 110 a to receivethe wheel assembly 120. In the example shown in FIGS. 5 and 6, themounting portion 110 a may open upwardly from a lower portion or surfaceof the cleaner main body 110.

A first connector 130 may be provided on an inner surface of themounting portion 110 a. The first connector 130 may be provided on theinner surface of the mounting portion 110 a to face an opening 110 a′ ofthe mounting portion 110 a. For example, the first connector 130 may bepositioned on a top surface or top portion of the mounting portion 110 aand may extend downward toward the floor surface. The first connector130 may be electrically connected to the controller. For example, thecontroller may forward control and/or driving signals to the firstconnector 130 and may receive signals from the first connector 130identifying a status of the wheel assembly 120.

The wheel assembly 120 may be provided with a second connector 127. Thesecond connector 127 may be electrically connected to an electroniccomponent of the wheel assembly 120. For example, the second connector127 may be electrically connected to the driving module 122. An electricwire (not shown) may be used for the electric connection between thewheel assembly 120 and the electronic component, and the electric wiremay be positioned outside of the wheel cover 121.

The second connector 127 may be configured to be coupled to the firstconnector 130 when the wheel assembly 120 is received in the mountingportion 110 a. For example, the second connector 127 may be positionedon the wheel cover 121 and opposite to the first connector 130 on anupper portion of the wheel assembly 120, and the second connector 127may face the inner surface of the mounting portion 110 a when the wheelassembly 120 is received in the mounting portion 110 a.

A direction in which the first connector 130 and the second connector127 are connected to each other may correspond to a direction in whichthe wheel assembly 120 is received in the mounting portion 110 a. Forexample, the mounting portion 110 a may guide a movement of the wheelassembly 120 into the cleaner main body 110 so that the first connector130 and the second connector 127 are accurately positioned to be coupledtogether when the wheel assembly 120 is inserted into the mountingportion 110 a.

When the wheel assembly 120 is inserted into the mounting portion 110 aformed in bottom portion of the cleaner main body 110 according to theaforementioned structure, the first connector 130 provided in themounting portion 110 a may be automatically connected to the secondconnector 127 provided on the wheel assembly 120. For example, the firstconnector 130 may include pins that are received in correspondingsockets formed in the second connector 127. This connection of the firstconnector 130 and the second connector 127 may facilitate the mountingand the electric connection of the wheel assembly 120 to the cleanermain body 110. In addition, when the wheel assembly 120 is notfunctioning correctly, the wheel assembly 120 can be detached from thecleaner main body 110 for inspection, repair, replacement, etc. Thisconfiguration may facilitate maintenance of the wheel assembly 120.

The wheel assembly 120 may be firmly fixed to the cleaner main body 110by a coupling unit (or coupling extension) when the wheel assembly 120is received in the mounting portion 110 a, and the first and secondconnectors 130 and 127 are connected to each other. The coupling unitmay include, for example, a hook coupling structure, a screw couplingstructure, or other connecting structure between the wheel assembly 120and the mounting portion 110 a. FIGS. 3-6 shown a coupling unit that mayinclude coupling holes 121 d formed through the wheel cover 121, andcoupling members (or screws) 111 that may be inserted into bosses orother receiving structures in the cleaner main body 110 through thecoupling holes 121 d to couple the wheel cover 121 to the cleaner mainbody 110.

As previously described, the second connector 127 may be electricallyconnected to the driving module 122, such as to forward a drivingcurrent from the controller to the driving module 122. The secondconnector 127 may also be electrically connected to a switch 126 or acliff sensor 129 included in the wheel module 120.

The switch 126 may be configured to detect a downward movement of thedriving wheel 123 relative to the cleaner main body 110. The switch 126may be electrically connected to the controller via the first connector130 and the second connector 127 to transmit a sensing signal (e.g., asignal identifying an amount of sagging detected by the switch 126).This detection signal forwarded from the switch 126 to the controllerwill be described in greater detail below.

The cliff sensor 129 may include a light emitting portion (or lightemitter) and a light receiving portion (or light sensor). The cliffsensor 129 may be configured to measure a distance to the floor surface,for example, by measuring a round trip time delay between an emission oflight from the light emitting portion toward the floor and detection bythe light receiving portion of light reflected from the floor. When thefloor moves away from the cleaner 100 such that a distance between thecliff sensor 129 and the floor increases, the time between the emissionand the reception of the light may drastically increase. Furthermore,when a cliff (e.g., a portion of the floor that is more than a thresholddistance below the cliff sensor 129) is present under the cliff sensor129, the light receiving portion may not detect any reflected light dueto scattering the light. Therefore, physical attributes of the floorsurface below the wheel assembly 120 may be detected by the cliff sensor129.

The controller may be configured to control an operation of the drivingmodule 122 based on the detection results by the cliff sensor 129. Forexample, when the cliff sensor 129 detects an obstacle associated withthe floor surface is at least a threshold distance below the wheelassembly 120, the controller may apply a driving signal to the drivingmodule 122 so that the cleaner 100 reverses to travel in an oppositedirection away from a detected obstacle. Alternatively, the controllermay apply a driving signal only to the driving module 122 of one of thewheel assemblies 120 or apply different driving signals to the left andright wheel assemblies 120 so that the cleaner 100 rotates to turn awayfrom the obstacle.

Although an electric connection structure including the first connector130 in a receiving cavity 110 a on a bottom portion of the cleaner mainbody 110 and a second connector 127 on an inserted item is describedhere with respect to the wheel module 120, it should be appreciated thata similar electrical connection structure may also be used with othercomponents mounted on the cleaner main body 110.

For example, the cleaner main body 110 may receive a battery 190 thatsupplies power to the cleaner 100. The battery 190 may be configured tobe rechargeable, and may be detachably provided in a batteryaccommodating portion (or battery accommodating recesses) formed on thelower portion of the cleaner main body 110 (see FIG. 5). The batteryaccommodating portion may be formed in a shape corresponding to thebattery 190, and a third connector (not shown) may be provided on aninner surface of the battery accommodating portion to face an opening ofthe battery accommodating portion. A fourth connector (not shown) matingto the third connector may be provided on an upper surface of thebattery 190, and this fourth connector may face the inner surface of thebattery accommodating portion when the battery 190 is inserted into thebattery accommodating portion. With this structure, when the battery 190is received in the battery accommodating portion, the third connectorand the fourth connector may be coupled to each other to enable anelectrical connection, such as to provide a path for carrying anelectrical current from battery 190 to the cleaner main body 110.

FIGS. 7 and 8 show exploded perspective views of the wheel assembly 120viewed from different directions, and FIG. 9 shows a sectional view ofthe wheel assembly 120 taken along the line A-A. Referring to FIGS. 7 to9, the wheel assembly 120 may include the wheel cover 121, the drivingmodule 122, the driving wheel 123, and a suspension 124.

The wheel cover 121 may be provided in the wheel assembly 120 to coveror enclose upper portions (e.g., portions within the main cleaner body110) of the driving wheel 123 and the driving module 122, and the wheelassembly 120 may be detachably coupled to the cleaner main body 110. Aspreviously described, the second connector 127, to be connected to thefirst connector 130 when the wheel assembly 120 is received in themounting portion 110 a, may be provided on a top portion or surface ofthe wheel cover 121. Coupling holes 121 d may be formed through a lowerportion of the wheel cover 121, and coupling members 111 may be insertedtherethrough to affix the wheel cover 121 to the cleaner main body 110.

The driving module 122 may be configured to generate a driving force andto transmit the driving force to the driving wheel 123. The drivingmodule 122 may be coupled to the wheel cover 121 so as to be verticallymovable, such as to move upward or downward relative to the wheel cover121. The vertical movement of the driving module 122 may be guided byguide bars 124 a of the suspension 124. The detailed configuration ofthe driving module 122 will be described in greater detail below.

The driving wheel 123 may be coupled to the driving module 122, and thedriving wheel 123 may rotate based on receiving the driving force fromthe driving module 122. The driving wheel 123 may also be configured tobe vertically movable with the driving module 122 within the wheel cover121.

The suspension 124 may guide the vertical movement of the driving module122 and may absorb impacts while the driving module 122 is verticallymoved. For example, the suspension 124 may reduce impacts applied to thecleaner main body 110 when the driving wheel 123 rolls over an unevenportion on the flow surface.

The suspension 124 may include the guide bar (or strut) 124 a and anelastic member (or spring) 124 b. The guide bar 124 a may be configuredto guide the vertical movement of the driving module 122. The guide bar124 a may be formed to extend in one direction and may be exposed aboveand below the wheel cover 121 through the driving module 122. FIGS. 7and 8 illustrate that separate guide bars 124 a may be provided to beinserted into the left and right sides of the driving module 122 (e.g.,into through-hole 122 a 1 a included in the module 122).

Upper and lower ends of the guide bar 124 a may be fixed to the wheelcover 121. FIGS. 7 and 8 illustrate that the upper end of the guide bar124 a may be fixed to a first fixing portion (or first fixing surface)121 a formed on a top portion of the wheel cover 121, and the lower endof the guide bar 124 a may be fixed to a second fixing portion (orsecond fixing surface) 121 b formed on a bottom portion of the wheelcover 121. The first fixing portion 121 a and the second fixing portion121 b are formed to face each other in an up and down direction of thewheel cover 121. The guide bar 124 a may guide the driving module 122 tobe vertically movable between the first fixing portion 121 a and thesecond fixing portion 121 b. For example, the driving module 122 mayslide along the guide bar 124 a between the first fixing portion 121 aand the second fixing portion 121 b.

The elastic member 124 b may be configured to absorb impacts while thedriving module 122 is vertically moved along the guide bar 124 a. Theelastic member 124 b may be connected to the wheel cover 121 and thedriving module 122, respectively. The elastic member 124 b may be formedas a coil spring that surrounds the guide bar 124 a and may be connectedto the first fixing portion 121 a of the wheel cover 121 and the upperportion of the driving module 122. Although not illustrated, the wheelmodule 120 may also include another elastic member that is connected,for example, to the second fixing portion 124 b of the wheel cover 121and the lower portion of the driving module 122.

FIG. 10 illustrates a state in which the driving wheel 123 is movedupward in the wheel assembly 120 relative to the wheel cover 121, andFIG. 11 illustrates a state in which where the driving wheel 123 ismoved downward in the wheel assembly 120 relative to the wheel cover121. Referring to FIGS. 10 and 11, the driving module 122 may beconfigured to be vertically movable with respect to the wheel cover 121along the guide bars 124 a of the suspension 124, as previouslydescribed. The driving wheel 123 may be coupled to the driving module122 and, thus, may move together with the driving module 122. That is,the driving wheel 123 may be configured to be vertically movable uptogether with the driving module 122 when a top portion of the drivingwheel 123 is covered with the wheel cover 121. The upward or downwardvertical movement of the driving module 122 and the driving wheel 123may help to buffer forces received by the driving wheel 123 from thefloor so that the driving wheel 123 may remain in contact with thefloor.

As previously described, FIG. 10 illustrates a first (compressed) statein which the driving wheel 123 moves upward relative to the cover 121and toward the cleaner main body 110 to compress the elastic member 124b. For example, FIG. 10 may illustrate a state in which a weight of thecleaner main body 110 is loaded on the driving wheel 123, such that theforce from the weight of the cleaner main body 110 moves the drivingwheel 123 relatively closer to the cleaner main body 110 within thewheel cover 121. For example, in normal operation, the cleaner main bodymay be supported by the driving wheel 123 while the driving module 122applies a driving force to move the cleaner main body 110 along thefloor surface. As illustrated in FIG. 10, a center of the driving wheel123 may be located within the wheel cover 121, and in certainconditions, the driving wheel 123 may move upwards to be fullyaccommodated in the wheel cover 121.

FIG. 11 illustrates a second (extended) state in which the driving wheel123 extends fully downward. For example, FIG. 11 may illustrate a statein which the driving wheel 123 in not in contact with the floor suchthat the elastic member 124 b is fully extend and not compressed (e.g.,the driving module 122 is moved by the elastic member 124 b to contactthe second fixing portion 121 b. This second state may be understood ascorresponding, for example, to the driving wheel 123 being lifted awayfrom the floor because the cleaner main body 110 is caught by anobstacle (e.g., a peak in the floor), or the cleaner main body 110 islifted off the floor by the user. In the second state, the driving wheel123 is accommodated in the wheel cover 121 at a relatively minimumlevel. For example, as illustrated in FIG. 11, the center of the drivingwheel 123 may be located below the wheel cover 121.

The particular positioned of the driving wheel 123 within the wheelassembly 120 with respect to the floor may vary depending on a state orcondition of the floor while the cleaner main body 110 travels. Thedriving wheel 123 may move up and down between the first compressedstate illustrated in FIG. 10 and the second state illustrated in FIG. 11depending on, for example, whether the driving wheel 123 contacts thefloor while the cleaner main body 110 is traveling. In this example, theelastic members 124 b may also elastically support the driving module122 connected to the driving wheel 123. With this structure, a groundingfunction (e.g., maintaining a contact between the driving wheel 123 tothe floor) and an impact buffering function to cushion impacts to thedriving wheel 123 can be concurrently performed, irrespective of arotating direction of the driving wheel 123. Therefore, a travelstability of the cleaner 100 can be improved.

FIG. 12 is an exploded perspective view of the driving module 122, andFIG. 13 is a sectional view of the wheel assembly 120 taken along theline B-B. Referring to FIGS. 12 and 13, the driving module 122 mayinclude a case 122 a, the driving motor 122 b, and a planetary geardevice (or planetary gear train) 122 c.

The driving motor 122 b may be mounted on one side of the case 122 a,and the driving motor 122 b may be electrically connected to the secondconnector 127, such that the driving motor 122 b may receive drivingpower from the cleaner main body 110 (e.g., from the controller). Aspreviously described, a through-hole 122 a 1 a through which the guidebar 124 a is inserted may be formed through the case 122 a. Separatethrough-holes 122 a 1 a may be formed on both right and left sides ofthe case 122 a. The case 122 a may be configured to be verticallymovable along the guide bar 124 a.

The planetary gear device 122 c may connect the driving motor 122 b andthe driving wheel 123, and the planetary gear device 122 c may modify adriving force produced by the driving motor 122 b. For example, thedriving motor 122 b may have rotating shaft that rotates at a particularrotation speed (e.g., revolution per minute (RPM)) to output a drivingforce, and the planetary gear device 122 c may modify the rotationalspeed and apply the reduced rotational speed to the driving wheel 123.The planetary gear device 122 c may be provided on another side of thecase 122 a. The planetary gear device 122 c may include one or morestages. In the example, shown in FIG. 12, the planetary gear device 122c may include two stages.

A sun gear 122 c 1 a may be is mounted on a rotating shaft of thedriving motor 122 b, and the driving wheel 123 may be mounted on thecase 122 a that rotatably supports a rotating shaft of each of aplurality of planetary gears. With this structure, the rotating shaft ofthe driving motor 122 b and the rotating axis of the driving wheel 123may be coaxially provided.

Referring back to FIGS. 6 and 8, an accommodating portion (oraccommodating cavity) 123 a to accommodate or receive at least part ofthe driving module 122 may be formed inside the driving wheel 123. Theplanetary gear device 122 c may be completely contained in theaccommodating portion 123 a such that a periphery of the planetary geardevice 122 c may be surrounded by the driving wheel 123. In this examplein which the planetary gear device 122 c is positioned in theaccommodating portion 123 a, the planetary gear device 122 c may notvisible from outside of the driving wheel 123.

As such, a gear device for reducing the rotational speed of the drivingmotor 122 b and transmitting the reduced rotational speed to the drivingwheel 123 can be configured as the planetary gear device 122 c so thatthe rotating shaft of the driving motor 122 b and a rotating shaft oraxis of the driving wheel 123 may be coaxially placed. Furthermore, thisstructure may also enable the planetary gear device 122 c to beaccommodated inside the accommodating portion 123 a formed inside thedriving wheel 123 so that a width or other size of a structure relatedto the operation of the driving wheel 123 can be miniaturized. Thisminimizing of a size of the planetary gear device 122 c may contributeto miniaturization of the overall size of the cleaner 100 or to enablean increase in a volume of another component of the cleaner 100 (forexample, the dust container 160).

In order to obtain an appropriate rational speed reduction ratio, theplanetary gear device 122 c may include a first planetary gear part (ora first planetary gear stage) 122 c 1 and a second planetary gear part(or a second planetary gear stage) 122 c 2. The first planetary gearpart 122 c 1 may be interlocked with the rotating shaft of the drivingmotor 122 b. The second planetary gear part 122 c 2 may be interlockedwith the first planetary gear part 122 c 1 and connected to the drivingwheel 123.

As shown in FIG. 12, the case 122 a may include a main case (or firstcase) 122 a 1, a middle case (or second case) 122 a 2, and a front case(or third case) 122 a 3. The main case 122 a 1 may have a through-hole122 a 1 a through which the guide bar 124 a is inserted, as previouslydescribed. The driving motor 122 b may be mounted on one side of themain case 122 a 1, and the first planetary gear part 122 c 1 may beaccommodated in another side of the main case 122 a 1. A sun gear 122 c1 a on the rotating shaft of the driving motor 122 b may be insertedthrough the main case 122 a 1. The cover 122 d may be provided to coverthe driving motor 122 b and may be coupled to the main case 122 a 1.

The first planetary gear part 122 c 1 may include a first sun gear 122 c1 a, a first ring gear 122 c 1 b, a plurality of first planetary gears122 c 1 c, and a first cage 122 c 1 d. The first sun gear 122 c 1 a maybe coupled to the rotating shaft of the driving motor 122 b and may beexposed to the another side of the main case 122 a 1 through a hole 122a 1′. In one example, the first sun gear 122 c 1 a may be configured tobe bidirectionally rotatable according to a driving signal applied fromthe controller.

The first ring gear 122 c 1 b may be provided on another side of themain case 122 a 1 (e.g., opposite the drive motor 122 b) to receive thefirst sun gear 122 c 1 a. The first sun gear 122 c 1 a may be providedat a center of the first ring gear 122 c 1 b. As illustrated in FIG. 12,the first ring gear 122 c 1 b may alternatively be formed on the maincase 122 a 1 itself.

The plurality of first planetary gears 122 c 1 c may engage the firstsun gear 122 c 1 a and the first ring gear 122 c 1 b, so as to rotate bythemselves and to simultaneously revolve around the first sun gear 122 c1 a. In the structure in which the first ring gear 122 c 1 b is fixed,the rotating direction of each of the plurality of first planetary gears122 c 1 c may be opposite to the rotating direction of the first sungear 122 c 1 a, and the revolving direction thereof may be the same asthe rotating direction of the first sun gear 122 c 1 a.

The first cage 122 c 1 d may rotatably support the rotating shaft ofeach of the plurality of first planetary gears 122 c 1 c. The first cage122 c 1 d may be arranged to cover a part of each of the plurality offirst planetary gears 122 c 1 c. The first cage 122 c 1 d may bearranged to cover the first sun gear 122 c 1 a, and in this case, mayalso be configured to rotatably support the rotating shaft of the firstsun gear 122 c 1 a.

The middle case 122 a 2 may be coupled to the main case 122 a 1. Oneside of the middle case 122 a 2 may cover the first planetary gear part122 c 1 and the second planetary gear part 122 c 2 may be accommodatedin another side of the middle case 122 a 2. A hole 122 a 2′ enabling aconnection between the first planetary gear part 122 c 1 and the secondplanetary gear part 122 c 2 may be formed through the middle case 122 a2.

The second planetary gear part 122 c 2 may include a second sun gear 122c 2 a, a second ring gear 122 c 2 b, a plurality of second planetarygears 122 c 2 c, and a second cage 122 c 2 d. The second sun gear 122 c2 a may protrude from the first cage 122 c 1 d and may be exposed at theanother side the middle case 122 a 2 through the hole 122 a 2′.

The second ring gear 122 c 2 b may be provided on the another side ofthe middle case 122 a 2 to surround the second sun gear 122 c 2 a. Thesecond sun gear 122 c 2 a may be provided at a center of the second ringgear 122 c 2 b. As illustrated in FIG. 12, the second ring gear 122 c 2b may be formed on an interior radial surface of the middle case 122 a 2itself.

The plurality of second planetary gears 122 c 2 c may engage with thesecond sun gear 122 c 2 a and the second ring gear 122 c 2 b and, thus,may rotate by themselves and may simultaneously revolve around thesecond sun gear 122 c 2 a. When the second ring gear 122 c 2 b is fixed,a rotating direction of each of the plurality of second planetary gears122 c 2 c may be opposite to the rotating direction of the second sungear 122 c 2 a, and the revolving direction thereof may correspond tothe rotating direction of the second sun gear 122 c 2 a.

The second cage 122 c 2 d may rotatably support the rotating shaft ofeach of the plurality of second planetary gears 122 c 2 c. The secondcage 122 c 2 d may cover the second planetary gears 122 c 2 c. Thesecond cage 122 c 2 d may cover the second sun gear 122 c 2 a, and inthis case, may rotatably support the rotating shaft of the second sungear 122 c 2 a.

The front case 122 a 3 may be coupled to the middle case 122 a 2 so asto cover the second planetary gear part 122 c 2. A hole 122 a 3′ toenable a connection between the second planetary gear part 122 c 2 andthe driving wheel 123 may be formed through the front case 122 a 3.

The second cage 122 c 2 d may include a protruding portion that isinserted into the hole 122 a 3′, and the protruding portion may includea coupling protrusion 122 c 2 d′ that engages a coupling groove 123 b ofthe driving wheel 123. Since the coupling protrusion 122 c 2 d′ engagesthe coupling groove 123 b, the driving wheel 123 may receive the drivingforce through the planetary gear device 122 c and rotate based onreceiving the driving force. A coupling member (or screw) 128 may becoupled to the second cage 122 c 2 d through the driving wheel 123 tofirmly affix the driving wheel 123 to the planetary gear device 122 c.

Portion (a) of FIG. 14 shows the driving module 122 being is movedupward in the wheel assembly 120 as viewed from a front surface (e.g.,opposite to the drive motor 122 b), and portion (b) of FIG. 14 shows thedriving module 122 being moved upward in the wheel assembly 120 asviewed from a rear surface (e.g., corresponding to a position of thedrive motor 122 b). Portion (a) of FIG. 15 shows the driving module 122being moved downward in the wheel assembly 120 as viewed from a frontsurface, and portion (b) of FIG. 15 shows the driving module 122 beingmoved downward in the wheel assembly 120 as viewed from the rearsurface. FIG. 16 is a conceptual view illustrating a link member 125illustrated in FIG. 14. FIG. 14 may correspond to the first stateillustrated in FIG. 10, and FIG. 15 may correspond to the second stateillustrated in FIG. 11. It should be noted that in portion (a) of FIG.14 and portion (a) of FIG. 15, the driving wheel 123 is omitted forconvenience of explanation.

Referring to FIGS. 14 to 16, the driving module 122 may be configured tobe vertically movable along the guide bars 124 a of the suspension 124.The driving wheel 123 may be coupled to the driving module 122 and,thus, may move together with the driving module 122.

FIG. 14 illustrates the first state in which the driving module 122moves upward, such as moving upward based on supporting a weight of thecleaner main body 110. Thus, FIG. 14 shows a situation in which thedriving wheel 123 contacts the floor surface and supports the cleanermain body 110. In this first state, the planetary gear device 122 c maybe fully accommodated in the wheel cover 121. As illustrated in FIG. 14,a center of the planetary gear device 122 c may be located in the wheelcover 121.

In the first state, an upper end of the case 122 a of the driving module122 may be positioned to be spaced apart from the second fixing portion121 b by a maximum distance. The upper end of the case 122 a may bepositioned adjacent to the first fixing portion 121 a. In the firststate, the elastic member 124 b connected to the first fixing portion121 a and the case 122 a, respectively, may be compressed to a maximumextent, such as to be compressed against the first fixing portion 121 a.

FIG. 15 illustrates the second state in which the driving module 122 ismoved downward to the maximum. This position may indicate that thedriving wheel 123 does not contact on the floor. In the second state,the planetary gear device 122 c may be accommodated in the wheel cover121 to a minimum extent. As illustrated in FIG. 15, the center of theplanetary gear device 122 c may be located below the wheel cover 121. Inthe second state, the case 122 a of the driving module 122 may beextended to an extent allowed by the second fixing portion 121 b. Thatis, the case 122 a may be contact the second fixing portion 121 b,thereby restricting any further downward movement of the driving module122. The upper end of the case 122 a may be spaced apart from the firstfixing portion 121 a by a maximum distance.

In the second state, the elastic member 124 b connected to the firstfixing portion 121 a and the case 122 a respectively may be pulled tothe maximum distance. For example, the case 122 a of the driving module122 is configured to be vertically movable by the guide bar 124 abetween the first fixing portion 121 a fixing the upper end of the guidebar 124 a and the second fixing portion 121 b fixing the lower end ofthe guide bar 124 a. The upward movement of the case 122 a may berestricted due to the maximum compression of the elastic member 124 b,and the downward movement of the case 122 a may be restricted due to thecase 122 a being locked by the second fixing portion 121 b.

Meanwhile, the cleaner 100 may be configured to control the rotation ofthe driving wheel 123 by physically detecting when the driving wheel 123is not in contact with the floor. Specifically, a link member 125 may berotatably mounted on the wheel cover 121. In the example shown in FIG.15, the link member 125 may be rotatably installed on a mounting portion121 c that is connecting the first fixing portion 121 a and the secondfixing portion 121 b.

The link member 125 may include a first link 125 a and a second link 125b that are coupled together. The first link 125 a may be provided on onesurface of the mounting portion 121 c, and the second link 125 b may beprovided on another surface of the mounting portion 121 c. The first andsecond links 125 a and 125 b may be coupled to each other and may rotatetogether. For the coupling, a coupling portion may protrude from one ofthe first and second links 125 a and 125 b, and a coupling hole 125 b′in which the coupling portion is inserted may be formed on another oneof the first and second links 125 a and 125 b.

The coupling hole 125 b′ may preferably be formed in a non-circular formto prevent the coupling portion from loosening when the coupling portionis inserted therein. The coupling portion may be provided with acoupling protrusion 125 a′ protruding into a shape corresponding to thecoupling hole 125 b′ to be inserted into the coupling hole 125 b′, andan elastic pin 125 a″ protruding from the coupling protrusion 125 a′ andlocking when inserted through the coupling hole 125 b′ so as to preventseparation of the first and second links 125 a and 125 b.

The link member 125 may be rotated when pressed or otherwise contactedbased on the vertical movement of the driving wheel 123 within the wheelassembly 120. For example, when the pressed link member 125 is released,the link member 125 may rotate in an opposite direction due to a forceapplied by an elastic member (not illustrated) to return to an originalposition.

A rotation guide 121 e that limits a rotation range of the first link125 a may be formed on one surface of the mounting portion 121 c tosurround a part of the first link 125 a. That is, the first link 125 amay be locked by the rotation guide 121 e and its rotation range may belimited accordingly.

The first link 125 a may rotate to be brought into contact with aprotrusion 122 a 1 b formed on the case 122 a when the case 122 a of thedriving module 122 moves downward by a preset distance. The protrusion122 a 1 b may protrude from a side portion of the case 122 a of thedriving module 122 and may be inclined to smoothly press the first link125 a.

As illustrated in FIG. 14, the protrusion 122 a 1 b and the first link125 a may be spaced apart from each other when the upper end of the case122 a is spaced apart from the second fixing portion 121 b by apredetermined distance. As the case 122 a gradually moves downward, theprotrusion 122 a 1 b and the first link 125 a may gradually move closerto each other. When the case 122 a is further moved downward when theprotrusion 122 a 1 b and the first link 125 a are in contact with eachother, the protrusion 122 a 1 b may press against and rotate the firstlink 125 a.

The rotation, as illustrated in FIG. 15, may continue until the case 122a is locked by the second fixing portion 121 b. As described above, whenthe case 122 a is locked by the second fixing portion 121 b indicatesthat the driving wheel 123 is not contacting the floor and notsupporting the weight of the cleaner main body 110, that is, the drivingwheel 123 is fully extended without being brought into contact with thefloor.

The switch 126 may be pressed in response to the rotation of the secondlink 125 b and may be provided on the another surface of the mountingportion 121 c where the second link 125 b is located. The switch 126 maybe mounted on the wheel cover 121 and may be electrically connected tothe second connector 127. When the case 122 a is locked by the secondfixing portion 121 b, the second link 125 b connected to the first link125 a may press or otherwise activate the switch 126, and the pressedswitch 126 may transfer a pressing signal to the controller.

When the switch 126 is pressed, the controller may control the operationof the driving motor 122 b. For example, when the switch 126 is pressed,the controller may stop the operation of the driving motor 122 b toprevent the rotation of the driving wheel 123. The control may beperformed, for example, when the switches 126 provided on the respectiveleft and right driving wheels 123 of the cleaner main body 110 are allpressed (e.g., none of the wheels 123 is contacting the floor). This maybe understood as stopping the rotating of the driving wheels 123 whenthe cleaner main body 110 is lifted by the user.

As another example, when a switch 126 provided on one of the left andright driving wheels 123 of the cleaner main body 110 is pressed, thecontroller may operate the driving motor 122 b in an opposite directionso that the driving wheel 123 is rotated in the opposite direction. Thismay be understood as a control for escaping an obstacle when one of thedriving wheels 123 is idled due to the cleaner main body 110 beingcaught by the obstacle. For example, a portion of the cleaner main body110 may be lifted by an obstacle such the one driving wheel 123 is notin contact with the floor surface while another driving wheel 123contacts the floor surface, and the controller may direct driving poweronly to driving wheel 123 that contacts the floor surface/

As aforementioned, when one driving wheel 123 loses contact with thefloor, the loss of contact by that driving wheel 123 can be detected bya mechanism that the protrusion of the driving module 122 rotates thelink member 125 and the rotated link member 125 presses the switch 126when the driving module 122 is moved downward by a preset distance.Accordingly, that driving wheel 123 that does not contact the floorsurface can be controller (e.g., stopped) so that stability of thecleaner can be improved and the user's satisfaction can be improved.

The foregoing description has been given of the detailed structure ofthe wheel assembly 120 on the basis of the structure in which the wheelassembly 120 is detachably coupled to the cleaner main body 110.However, certain components, such as the driving module 122, thesuspension 124, the link member 125, the switch 126, and/or the cliffsensor 129 may be mounted on the cleaner main body 110 and without beingincluded in the wheel assembly 110. In this alternative configuration,the function of the wheel cover 121 described above may be substitutedby a wheel housing of the cleaner main body 110. For example, the wheelhousing may be formed to surround an upper portion of the driving wheel123.

For example, the wheel housing may be provided with the first and secondfixing portions 121 a and 121 b on which the guide bar 124 a may bemounted. The link member 125 may be rotatably mounted on the mountingportion 121 c of the wheel house, and the switch 126 may also be mountedon the mounting portion 121 c of the wheel house. The cliff sensor 129may be provided on the wheel house or the lower portion of the cleanermain body 110 adjacent to the wheel house.

Also, the foregoing description has been given exemplarily of a robotcleaner, to which the present disclosure is applied. The robot cleaneris merely illustrative to help understanding the example to which thepresent disclosure is applied, but it should not be construed that thepresent disclosure is applied only to the robot cleaner. That is, theabove-described structure can be applied to any structure having thedriving wheel 123 that is rotated by driving force in every type ofcleaner such as a canister type, an upright type and the like.

A first aspect of the present disclosure is to provide a cleaner,capable of exhibiting the same suspension performance regardless of arotating direction of a driving wheel. A second aspect of the presentdisclosure is to provide a cleaner having a miniaturized structureassociated with an operation of a driving wheel. A third aspect of thepresent disclosure is to provide a cleaner, in which a structureassociated with an operation of a driving wheel can be mounted on acleaner main body so as to be electrically connected to the cleaner mainbody, and of which repair is facilitated. A fourth aspect of the presentdisclosure is to provide a cleaner, capable of controlling a rotation ofa driving wheel by physically detecting a state where a driving wheel isnot brought into contact with a floor surface.

To achieve the first aspect of the present disclosure, there is provideda cleaner including a cleaner main body having a controller, a wheelcover mounted on the cleaner main body, a driving module coupled to thewheel cover to be movable up and down, a driving wheel coupled to thedriving module and configured to be rotatable by receiving driving forcefrom the driving module, a guide bar coupled to the wheel cover andprovided in an up and down direction, the guide bar being insertedthrough the driving module to guide the upward and downward movement ofthe driving module, and an elastic member surrounding the guide bar andconnected to the wheel cover and the driving module, respectively, toabsorb impacts while the driving module is moved up and down.

The first aspect of the present disclosure may also be achieved by acleaner, which includes a cleaner main body having a controller, adriving module provided with a case coupled to a wheel house of thecleaner body to be movable up and down, a driving motor mounted to thecase, and a planetary gear device for reducing revolution of the drivingmotor, a driving wheel connected to the planetary gear device to berotatable, a guide bar coupled to the wheel cover, provided in an up anddown direction, and inserted through the case to guide the upward anddownward movement of the case, and an elastic member surrounding theguide bar and connected to the wheel house and the case, respectively,to absorb impacts while the case is moved up and down.

To achieve the second aspect of the present disclosure, there isprovided a cleaner including a cleaner main body having a controller, awheel cover mounted to the cleaner main body, a driving module providedwith a case coupled to the wheel cover to be movable up and down, adriving motor mounted to the case, and a planetary gear device forreducing revolution of the driving motor, a driving wheel connected tothe planetary gear device to be rotatable, and a suspension configuredto guide the upward and downward movement of the case and absorb impactswhile the case is moved up and down. A rotating shaft of the drivingmotor and a rotating shaft of the driving wheel may be coaxiallyarranged, and the driving wheel may be provided with an accommodatingportion formed at an inner side thereof to accommodate the planetarygear device.

The second aspect of the present disclosure may also be achieved by acleaner which includes a cleaner main body having a controller, adriving module provided with a case coupled to a wheel house of thecleaner body to be movable up and down, a driving motor mounted to thecase, and a planetary gear device for reducing revolution of the drivingmotor, a driving wheel connected to the planetary gear device to berotatable, and a suspension configured to guide the upward and downwardmovement of the case and absorb impacts while the case is moved up anddown. A rotating shaft of the driving motor and a rotating shaft of thedriving wheel may be coaxially arranged, and the driving wheel may beprovided with an accommodating portion formed at an inner side thereofto accommodate the planetary gear device.

In order to achieve the third aspect of the present disclosure, there isprovided with a cleaner including a cleaner main body having a mountingportion recessed upwardly at a lower portion thereof, and a wheelassembly detachably mounted on the mounting portion. A first connectormay be provided on an inner surface of the mounting portion facing anopening of the mounting portion in a manner of facing the opening, and asecond connector may be provided on an upper portion of the wheelassembly, and may be connected to the first connector when the wheelassembly is accommodated in the mounting portion. The cleaner mayfurther include a coupling unit coupling the wheel assembly to thecleaner main body when the wheel assembly is accommodated in themounting portion.

In order to achieve the fourth aspect of the present disclosure, thereis provided a cleaner including a cleaner main body having a controller,a wheel cover mounted on the cleaner main body, a driving module coupledto the wheel cover to be movable up and down, a driving wheel coupled tothe driving module and configured to be rotatable by receiving drivingforce from the driving module, a suspension configured to guide the upand down movement of the driving module and absorb impacts while thedriving module is moved up and down, a link member rotatably installedon the wheel cover, and rotated by being in contact with a protrusionformed on the driving module when the driving module is moved downwardby a preset distance, and a switch pressed in response to the rotationof the link member to transmit a pressing signal to the controller.

The fourth aspect of the present disclosure may also be achieved by acleaner which includes a cleaner main body having a controller, adriving module provided with a case coupled to a wheel house of thecleaner main body to be movable up and down, a driving motor mounted tothe case, and a planetary gear device for reducing revolution of thedriving motor, a driving wheel connected to the planetary gear device tobe rotatable, a link member rotatably installed on the wheel house, androtated by being in contact with a protrusion formed on the case whenthe case is moved downward by a preset distance, and a switch pressed inresponse to the rotation of the link member to transmit a pressingsignal to the controller.

The aforementioned cleaner can be configured as follows. The drivingmodule may include a case having a through-hole into which the guide baris inserted, a driving motor mounted on the case, and a planetary geardevice connecting the driving motor and the driving wheel to each other,and reducing revolution of the driving motor to transfer the reducedrevolution to the driving wheel. The planetary gear device may include afirst planetary gear part interlocked with a rotating shaft of thedriving motor, and a second planetary gear part interlocked with thefirst planetary gear part and connected to the driving wheel.

The case may include a main case having the through-hole and the drivingmotor mounted thereon, and accommodating the first planetary gear parttherein, a middle case coupled to the main case to cover the firstplanetary gear part, and accommodating the second planetary gear part,and a front case coupled to the middle case to cover the secondplanetary gear part.

The first planetary gear part may include a first sun gear coupled to arotating shaft of the driving motor, a first ring gear formed on themain case and accommodating the first sun gear therein, a plurality offirst planetary gears engaged with the first sun gear and the first ringgear, rotating in an opposite direction to a rotating direction of thefirst sun gear, and revolving in the same direction as the rotatingdirection of the first sun gear centering on the first sun gear, and afirst cage rotatably supporting a rotating shaft of each of theplurality of first planetary gears.

The second planetary gear part may include a second sun gear provided onthe first cage, a second ring gear formed on the middle case andaccommodating the second sun gear therein, a plurality of secondplanetary gears engaged with the second sun gear and the second ringgear, rotating in an opposite direction to a rotating direction of thesecond sun gear, and revolving in the same direction as the rotatingdirection of the second sun gear centering on the second sun gear, and asecond cage rotatably supporting a rotating shaft of each of theplurality of second planetary gears.

The second cage may be provided with a coupling protrusion engaged witha coupling groove of the driving wheel to prevent the driving wheel frombeing idled. The wheel cover or the wheel house may include a firstfixing portion to which an upper end of the guide bar is fixed, and asecond fixing portion formed to face the first fixing portion, and towhich a lower end of the guide bar is fixed. The case may be configuredto be movable up and down by the guide bar between the first fixingportion and the second fixing portion.

The case may be locked by the second fixing portion when the case ismoved downward by a predetermined distance. The elastic member may beconnected to the first fixing portion and the case, respectively. Thecontroller may stop an operation of the driving motor when the switch ispressed.

The link member may include a first link exposed to one side of thewheel cover where the protrusion is located, and a second link coupledto the first link and exposed to another side of the wheel cover wherethe switch is located.

The effects of the present disclosure obtained by the aforementionedsolutions are as follows. First, a driving module coupled to a drivingwheel can be movable up and down along a guide bar and an elastic membercan absorb impacts generated while the driving module is moved up anddown, which may result in uniformly realizing a grounding function andan impact buffering function, irrespective of a rotating direction ofthe driving wheel.

Second, a gear device for reducing revolution of a driving motor andtransmitting the reduced revolution to a driving wheel can be configuredas a planetary gear device. Accordingly, a rotating shaft of the drivingmotor and a rotating shaft of the driving wheel can be coaxiallyarranged and the planetary gear device can be accommodated in anaccommodating portion formed inside the driving wheel, therebyminiaturizing a structure related to an operation of the driving wheel.This can contribute to miniaturization of the cleaner or to an increasein a volume of another component (for example, a dust container).

Third, when a wheel assembly is inserted into a mounting portion formedin a cleaner main body, a first connector provided on the mountingportion can be connected to a second connector provided on the wheelassembly, thereby facilitating mounting and electric connection of thewheel assembly to the cleaner main body. In addition, when the wheelassembly is in trouble, only the wheel assembly can be detached from thecleaner main body for inspection, repair, replacement, and the like.This may result in facilitating maintenance of the wheel assembly.

Fourth, in a situation that the driving wheel is not brought intocontact with the floor occurs, the rotation or revolution of the drivingwheel can be controlled (e.g., stopped) by a mechanism that a protrusionof the driving module rotates a link member and the rotated link memberpresses a switch when the driving module is moved downward by a presetdistance. This may result in improving stability and user'ssatisfaction.

Any reference in this specification to “one embodiment,” “anembodiment,” “example embodiment,” etc., means that a particularfeature, structure, or characteristic described in connection with theembodiment is included in at least one embodiment. The appearances ofsuch phrases in various places in the specification are not necessarilyall referring to the same embodiment. Further, when a particularfeature, structure, or characteristic is described in connection withany embodiment, it is submitted that it is within the purview of oneskilled in the art to effect such feature, structure, or characteristicin connection with other ones of the embodiments.

Although embodiments have been described with reference to a number ofillustrative embodiments thereof, it should be understood that numerousother modifications and embodiments can be devised by those skilled inthe art that will fall within the spirit and scope of the principles ofthis disclosure. More particularly, various variations and modificationsare possible in the component parts and/or arrangements of the subjectcombination arrangement within the scope of the disclosure, the drawingsand the appended claims. In addition to variations and modifications inthe component parts and/or arrangements, alternative uses will also beapparent to those skilled in the art.

What is claimed is:
 1. A cleaner, comprising: a cleaner body having acontroller; a wheel cover mounted to the cleaner body; a motor that isconnected to the wheel cover and generates a driving force; a drivingwheel that is coupled to the motor and rotates based on receiving thedriving force from the motor; a suspension that guides a verticalmovement of the motor and absorbs impacts during the vertical movementof the motor; a link that is rotatably installed on the wheel cover androtates based on contacting a protrusion connected to the motor when themotor moves downward by a prescribed distance; and a switch that isactivated during the rotation of the link and transfers a signal to thecontroller when activated, wherein the link includes: a first linkexposed to one surface of the wheel cover where the protrusion islocated; and a second link coupled to the first link and exposed toanother surface of the wheel cover where the switch is located.
 2. Thecleaner of claim 1, wherein the controller stops an operation of themotor when the switch is activated.
 3. The cleaner of claim 1, whereinthe suspension includes: a guide bar that is coupled to the wheel cover,extends vertically, and guides the vertical movement of the motor; and aspring that surrounds the guide bar, and is supported on the wheel coverand the motor, respectively, to absorb the impacts during the verticalmovement of the motor.
 4. The cleaner of claim 3, further comprising: acase having a through-hole into which the guide bar is inserted, whereinthe motor is mounted to the case; and a planetary gear train thatconnects the motor and the wheel and is configured to receive thedriving force from the motor and to transfer the driving force to thewheel.
 5. The cleaner of claim 4, wherein a rotating shaft of the motorand a rotating axis of the wheel are coaxially arranged.
 6. The cleanerof claim 4, wherein the wheel cover includes: a first fixing surface towhich an upper end of the guide bar is fixed; and a second fixingsurface formed to face the first fixing surface, and to which a lowerend of the guide bar is fixed, and wherein guide bar directs the case tomove vertically between the first fixing surface and the second fixingsurface.
 7. The cleaner of claim 6, wherein the second fixing surfaceblocks the case from moving more than a prescribed distance downward. 8.The cleaner of claim 6, wherein the spring is connected to the firstfixing surface and the case, respectively.
 9. The cleaner of claim 4,wherein the planetary gear train comprises: a first planetary gear stageinterlocked with a rotating shaft of the motor; and a second planetarygear stage interlocked with the first planetary gear stage and connectedto the wheel.
 10. The cleaner of claim 9, wherein the case includes: afirst case having the through-hole and the motor mounted thereon, andaccommodating the first planetary gear stage therein; a second casecoupled to the first case, provided to cover the first planetary gearstage, and accommodating the second planetary gear stage; and a thirdcase coupled to the second case and provided to cover the secondplanetary gear stage.
 11. The cleaner of claim 10, wherein the firstplanetary gear stage includes: a first sun gear coupled to the rotatingshaft of the motor; a first ring gear formed on the second case andaccommodating the first sun gear therein; a plurality of first planetarygears engaged with the first sun gear and the first ring gear, rotatingin an opposite direction to a rotating direction of the first sun gear,and revolving in the same direction as the rotating direction of thefirst sun gear centering on the first sun gear; and a first cagerotatably supporting rotating shafts of the plurality of first planetarygears.
 12. The cleaner of claim 11, wherein the second planetary gearstage includes: a second sun gear provided on the first cage; a secondring gear formed on the middle case and accommodating the second sungear therein; a plurality of second planetary gears engaged with thesecond sun gear and the second ring gear, rotating in an oppositedirection to a rotating direction of the second sun gear, and revolvingin the same direction as the rotating direction of the second sun gearcentering on the second sun gear; and a second cage rotatably supportingrotating shafts of the plurality of second planetary gears.
 13. Thecleaner of claim 12, wherein the second cage includes a couplingprotrusion that engages a coupling groove of the wheel.
 14. The cleanerof claim 1, wherein the driving wheel includes an accommodating recessformed at an inner side thereof to accommodate at least part of themotor.
 15. The cleaner of claim 1, wherein the cleaner body includes amounting recess that extends upwardly from a lower portion thereof,wherein a first connector is electrically connected to the controllerand is provided on an inner surface of the mounting recess to face anopening of the mounting recess, and wherein a second connector iselectrically connected to the motor and is provided on an upper portionof the wheel cover, the second connector being connected to the firstconnector when the wheel cover is received in the mounting portion. 16.A cleaner, comprising: a case that is coupled to a wheel housing of thecleaner body and that moves vertically in the wheel housing; a motorthat is mounted to the case; a planetary gear train that receives adriving force from the driving motor; a wheel that is connected to theplanetary gear train and rotates based on the receiving the drivingforce via the planetary gear train; a link that is rotatably connectedto the wheel housing, and is rotated by being in contact with aprotrusion formed on the case when the case is moved downward by aprescribed distance; and a switch that is activated during the rotationof the link and transfers a signal to a controller of the cleaner whenactivated, wherein the link includes: a first link exposed to onesurface of the case where the protrusion is located; and a second linkcoupled to the first link and exposed to another surface of the casewhere the switch is located.
 17. The cleaner of claim 16, wherein thecontroller modifies an operation of the motor based on receiving thesignal from the switch.
 18. The cleaner of claim 16, further comprising:a guide bar that is coupled to the wheel housing, extends in a verticaldirection, and is inserted through the case to guide a vertical movementof the case; and a spring that is provided to surround the guide bar,and is supported on the wheel housing and the case, respectively, toabsorb impacts while the case is moved vertically.
 19. A cleaner,comprising: a cleaner body having a controller; a wheel cover mounted tothe cleaner body; a motor that is connected to the wheel cover andgenerates a driving force; a driving wheel that is coupled to the motorand rotates based on receiving the driving force from the motor; asuspension that guides a vertical movement of the motor and absorbsimpacts during the vertical movement of the motor; a link that isrotatably installed on the wheel cover and rotates based on contacting aprotrusion connected to the motor when the motor moves downward by aprescribed distance; and a switch that is activated during the rotationof the link and transfers a signal to the controller when activated,wherein the driving wheel includes an accommodating recess formed at aninner side thereof to accommodate at least part of the motor.